Whilethusservinganapprenticeshiptojournalism，Millwasgoingthrougharemarkablementaltraining。Aboutthebeginningof1825heundertooktoeditBentham’sRationaleofEvidence。Hesaysthatthiswork’occupiednearlyallhisleisureforaboutayear。’Thatsuchataskshouldhavebeenaccomplishedbyayouthoftwentyinayearwouldseemmarvellousevenifhehadbeenexclusivelydevotedtoit。HehadtocondenselargemassesofBentham’scrabbedmanuscriptintoacontinuoustreatise；to’unroll’hisauthor’sinvolvedandparentheticsentences；toreadthestandardEnglishtextbooksuponevidence；toreplytoreviewersofpreviousworksofBentham，andtoaddcommentsespeciallyuponsomelogicalpoints。Finally，hehadtosee，fivelargevolumesthroughthepress。’18*Thatthiswasadmirablepractice，andthatMill’sstylebecameafterwards，markedlysuperior，towhatithadbeenbefore，maybewellbelieved。Itisimpossible，however，nottoconnectthefactthatMillhadgonethroughthislabourin1825withthesingularmentalconvulsionwhichfollowedin1826。
Hewas，hesays，ina，dullstateofnerves，intheautumnofthatyear。Itoccurredtohimtoaskwhetherhewouldbehappysupposingthatallhisobjectsinlifecouldberealised。’Anirrepressibleconsciousnessdistinctlyanswered“No。“’Thecloudwouldnotpassaway。Hecouldthinkofnophysicianofthemindwhocould’razeouttherootedtroubleofthebrain。’Hisfatherhadnoexperienceofsuchfeeling，norcouldhegivetheeldermanthepainofthinkingthatalltheeducationalplanshadfailed。Thefather’sphilosophy，indeed，bothexplained，andshowedthehopelessnessof，theevil。Feelingsdependuponassociation。Analysistendstodestroytheassociations，andthereforeto’wearawaythefeelings。’Happinesshasforitsmainsourcethepleasureofsympathywithothers。Buttheknowledgethatthefeelingwouldgivehappinesscouldnotsufficetorestorethefeelingitself。Itseemedtobeimpossibletosettoworkagainandcreatenewassociations。Milldraggedonmechanicallythroughthewinterof1826-27，andthegloomonlygathered。Hemadeuphismindthathecouldnotbearlifeformorethanayear。ThefirstrayofhopecamefromapassageinwhichMarmonteldescribeshisfather’sdeathandhisresolutiontomakeupthelosstohisfamily。Graduallyherecovered，thoughhesufferedseveralrelapses。Helearned，hesays，twolessons：
first，thatthoughhappinessmustbetheend，itmustnotbetheimmediateorconsciousend，oflife。Askwhetheryouarehappyandyouwillceasetobehappy。Fixuponsomeendexternaltohappiness，andhappinesswillbe’inhaledwiththeairyoubreathe。’Andinthesecondplace，helearnedtomakethe’cultivationofthefeelingsoneofthecardinalpointsinhisethicalandphilosophicalcreed。’Hecouldnot，however，forsometimeapplyhisnewdoctrinetopractice。Hementionsasaquaintillustrationofthisperiodoneingeniousmodeofself-torment。
Hehadfromchildhoodtakenpleasureinmusic。Duringtheperiodofdepressionevenmusichadlostitscharm。Asherevived，thecharmgraduallyreturned。Yetheteasedhimselfbythereflectionthat，asthenumberofmusicalnotesislimited，theremustcomeatimewhennewMozartsandWeberswouldnolongerbepossible。
This，hesays，waslikethefearoftheLaputansthatthesunwouldintimebeburntout，afear，itmayberemarked，whichmodernsciencehasnotdiminished。Hemighthavenoticedthat，asthenumberofcombinationsoftwenty-sixlettersisfinite，newShakespearesandDanteswillbecomeimpossible。Heobserves，however，thatthiswasconnectedwiththe’onlygoodpointinhisveryunromanticandinnowayhonourabledistress。’Itshowedaninterestinthefortunesoftheraceaswellasinhisown，andthereforegavehopesthatifhecouldseehiswaytobetterprospectsofhumanhappinesshisdepressionmightbefinallyremoved。ThisstateofmindmadehisreadingofWordsworth’sExcursionintheautumnof1828animportanteventinhislife。